U.S. patent application number 11/722248 was filed with the patent office on 2010-01-07 for h-type monopole isolation antenna.
This patent application is currently assigned to Electronics and Telecommunications Research Institute. Invention is credited to Soon-ik Jeon, Joung-myoun Kim, Ung-hee Park, Je-hoon Yun.
Application Number | 20100001922 11/722248 |
Document ID | / |
Family ID | 36601971 |
Filed Date | 2010-01-07 |
United States Patent
Application |
20100001922 |
Kind Code |
A1 |
Yun; Je-hoon ; et
al. |
January 7, 2010 |
H-TYPE MONOPOLE ISOLATION ANTENNA
Abstract
Provided is an H-type monopole isolation antenna. The antenna
provides an H-type monopole isolation antenna which can gain a high
bi-directional transmitting/receiving isolation between a
transmitting antenna and a receiving antenna of
co-channel/co-polarization by including an antenna symmetrically
positioned in right/left sides based on a covering means. A
transmitting/receiving isolation antenna for maintaining high
isolation between a transmitting signal and a receiving signal
includes a cover which includes a conductor; and first and second
antennas which are bisymmetrically positioned in right and left
parts of the covering means and separately operated as a
transmitting antenna or a receiving antenna. The antenna is used in
a co-channel bi-direction repeater system.
Inventors: |
Yun; Je-hoon; (Daejeon,
KR) ; Kim; Joung-myoun; (Daejeon, KR) ; Park;
Ung-hee; (Daejeon, KR) ; Jeon; Soon-ik;
(Daejeon, KR) |
Correspondence
Address: |
LADAS & PARRY LLP
224 SOUTH MICHIGAN AVENUE, SUITE 1600
CHICAGO
IL
60604
US
|
Assignee: |
Electronics and Telecommunications
Research Institute
Daejeon
KR
|
Family ID: |
36601971 |
Appl. No.: |
11/722248 |
Filed: |
December 21, 2005 |
PCT Filed: |
December 21, 2005 |
PCT NO: |
PCT/KR2005/004428 |
371 Date: |
June 20, 2007 |
Current U.S.
Class: |
343/879 ;
343/893 |
Current CPC
Class: |
H01Q 21/18 20130101;
H01Q 21/29 20130101; H01Q 9/16 20130101; H01Q 9/20 20130101 |
Class at
Publication: |
343/879 ;
343/893 |
International
Class: |
H01Q 1/52 20060101
H01Q001/52; H01Q 21/00 20060101 H01Q021/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 21, 2004 |
KR |
10-2004-0109404 |
Claims
1. A transmitting/receiving isolation antenna maintaining high
isolation between a transmitting signal and a receiving signal,
comprising: a covering means which includes an electric conductor;
and first and second antennas which are symmetrically positioned in
right and left parts of the covering means and operated as a
transmitting antenna or a receiving antenna respectively.
2. The transmitting/receiving isolation antenna as recited in claim
1, wherein the first antenna is an H-type monopole antenna.
3. The transmitting/receiving isolation antenna as recited in claim
2, wherein the second antenna is a monopole antenna.
4. The transmitting/receiving isolation antenna as recited in claim
1, wherein the covering means has a form of a housing having a
space inside.
5. The transmitting/receiving isolation antenna as recited in claim
1, wherein the first antenna, includes: a left antenna device which
is vertically attached to the covering means; a right antenna
device which is vertically attached to the covering means and
positioned closely to the left antenna device; an isolation
supporter which is vertically connected to each of the left antenna
device and right antenna device and isolates the left antenna
device and the right antenna device in parallel; and a first
antenna feeding means which is positioned in a center of the
isolation supporter.
6. The transmitting/receiving isolation antenna as recited in claim
5, wherein the left and right antenna devices and isolation
supporter are formed in a shape of a conductive pipe having a space
inside.
7. The transmitting/receiving isolation antenna as recited in claim
6, wherein the first antenna feeding means in which a part
connected to a feeding line is positioned inside the isolation
supporter to be connected to the feeding line inside the covering
means.
8. The transmitting/receiving isolation antenna as recited in claim
6, wherein the first antenna feeding means uses a connector.
9. The transmitting/receiving isolation antenna as recited in claim
5, wherein the first antenna feeding means is wrapped by a
dielectric.
10. The transmitting/receiving isolation antenna as recited in
claim 7, wherein the second antenna has a structure in which the
connector is used and includes a second antenna feeding means which
is connected to the feeding line through the inside of the covering
means.
11. The transmitting/receiving isolation antenna as recited in
claim 1, further comprising: a supporting means for supporting the
covering means by being connected to a lower central part of the
covering means.
12. The transmitting/receiving isolation antenna as recited in
claim 11, further comprising: a base for vertically fixing the
supporting means on a surface.
13. The transmitting/receiving isolation antenna as recited in
claim 12, wherein the base includes an electric wave absorbing
means for absorbing electric wave in an upper part of the base.
14. The transmitting/receiving isolation antenna as recited in
claim 11, wherein the supporting means includes a power accessing
means in one end.
15. The transmitting/receiving isolation antenna as recited in
claim 11, wherein the supporting means is formed in a shape of a
pipe having a space inside.
16. The transmitting/receiving isolation antenna as recited in
claim 1, wherein a feeding direction of the first antenna is
perpendicular to a surface contacting the covering means, and a
feeding direction of the second antenna is horizontal to a surface
connected to the covering means.
Description
TECHNICAL FIELD
[0001] The present invention relates to an H-type monopole
isolation antenna; and, more particularly, to an H-type monopole
isolation antenna for isolating a transmitting signal and a
receiving signal in a co-channel, a co-polarization and a
co-direction.
BACKGROUND ART
[0002] An isolation technology for separating
transmitting/receiving signals in an antenna has been studied for a
long time. The conventional isolation technology can be divided
into two technologies according to propagation direction.
[0003] The first one is a unidirectional repeater, i.e., an antenna
technology for receiving a receiving signal in the rear part and
transmitting an amplified signal in the front part. This technology
is used in a repeater system for co-channel broadcasting and it
will be called a unidirectional isolation technology hereinafter.
In the antenna technology, the transmitting signal is not
transmitted in a direction that the transmitting signal is
received, and a repeater for the co-channel broadcasting is used
representatively and generally.
[0004] Since the unidirectional isolation technology gains high
isolation by setting up high-directional antennas in opposition to
each other and spacing them from each other, the unidirectional
isolation technology has a shortcoming that it requires much space
for setup.
[0005] Therefore, a broadcasting repeater using the conventional
unidirectional isolation technology is used by setting up a
receiving antenna in the lower part of a high iron tower and a
transmitting antenna in the upper part.
[0006] The other conventional technology is a bi-directional
isolation technology for re-transmitting in a co-direction.
Specifically, there is a bi-directional isolation technology based
on polarization.
[0007] That is, the technology raises the degree of isolation of
the transmitting/receiving signals by generating polarizations of
the transmitting/receiving signals.
[0008] However, the conventional bi-directional isolation
technology has a problem that a distance length should be
sufficiently acquired between the receiving antenna, i.e., the
horizontal polarization and the transmitting antenna, i.e., the
vertical polarization.
[0009] Another conventional technology, which is not applied to a
practical system, generates the transmitting signal and the
receiving signal, whose polarizations are perpendicular to each
other, and maintains isolation between two terminals by vertically
setting up their feed in a patch antenna. This is revealed in an
article by Karode, in IEE National Conference on Antennas and
Propagation, pp. 49-52, April 1999).
[0010] Also, Hao has realized an isolation technology by
differentiating polarization generation of the patch antenna
applying a photo band gap (PBG) structure in an article published
in IEE, 11.sup.th International Conference on Antenna Propagation,
pp. 86-89, April 2001).
[0011] However, as shown in the result, since the isolation for a
co-frequency of the transmitting/receiving signals is very low, the
technology is not proper as an antenna for co-channel
bi-directional communications in diverse fields of mobile
communications, short distance communications, a broadcasting
repeater and satellite communications requiring high isolation for
the co-frequency.
[0012] In the result of the conventional technologies suggested by
Karodo and Hao, isolation is not more than about 60 dB although
transmitting/receiving frequency bands or polarizations are
different from each other.
[0013] Therefore, the isolation antenna, which is required for a
co-channel wireless Local Area Network (LAN) low output repeater, a
Radio Frequency (RF) reader antenna, an antenna for testing Radar
Cross Section (RCS), and an isolation antenna capable of
co-channel, co-polarization and bi-directional communications which
is necessary in co-channel bi-directional communication
devices.
DISCLOSURE OF INVENTION
Technical Problem
[0014] It is, therefore, an object of the present invention to
provide an H-type monopole isolation antenna which can gain a high
bi-directional transmitting/receiving isolation between a
transmitting antenna and a receiving antenna of
co-channel/co-polarization by including an antenna symmetrically
positioned in the right/left sides based on a a covering means
between them.
[0015] Other objects and advantages of the invention will be
understood by the following description and become more apparent
from the embodiments in accordance with the present invention,
which are set forth hereinafter. It will be also apparent that
objects and advantages of the invention can be embodied easily by
the means defined in claims and combinations thereof.
Technical Solution
[0016] In accordance with one aspect of the present invention,
there is provided a transmitting/receiving isolation antenna
maintaining high isolation between a transmitting signal and a
receiving signal, including: a cover which includes a conductor;
and first and second antennas which are symmetrically positioned in
right and left parts of the covering means and operated as a
transmitting antenna or a receiving antenna respectively.
[0017] In accordance with another aspect of the present invention,
the antenna further includes: a supporter for supporting the cover
by being connected to a lower central part of the cover and a base
for vertically fixing the supporter on a surface.
Advantageous Effects
[0018] The present invention can acquire high isolation more than
75 dB although the transmitting/receiving antennas are set up
adjacently and a small covering housing is used in a co-channel,
co-polarization and co-direction.
[0019] Also, the present invention can realize high isolation by a
small antenna and it can be applied to a bi-directional antenna or
an antenna requiring high bi-directional transmission/reception
isolation, such as a wireless Local Area Network (LAN), a Radio
Frequency Identification (RFID) reader, a monitoring system, a
Radar Cross Section (RCS) measuring system and a co-channel mobile
communication system.
[0020] Also, since the antenna of the present invention can be
fabricated in the form of a wall-hanging device or a device
integrated with a power outlet, it can widen a usage range and
independently realize the system in a small space.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The above and other objects and features of the present
invention will become apparent from the following description of
the preferred embodiments given in conjunction with the
accompanying drawings, in which:
[0022] FIG. 1 is a perspective view showing an H-type monopole
isolation antenna in accordance with an embodiment of the present
invention;
[0023] FIG. 2 is a cross-sectional front view showing the antenna
device in accordance with the embodiment of the present
invention;
[0024] FIG. 3 is a cross-sectional side view showing the antenna
device in accordance with the embodiment of the present
invention;
[0025] FIG. 4 is a cross-sectional plane view showing the antenna
device in accordance with the embodiment of the present
invention;
[0026] FIG. 5 is a graph showing an S parameter characteristic of
the H-type monopole isolation antenna in accordance with the
embodiment of the present invention;
[0027] FIG. 6 is a graph showing S.sub.12 parameter characteristics
based on the size of a covering housing of the H-type monopole
isolation antenna in accordance with the embodiment of the present
invention;
[0028] FIG. 7 is a smith chart showing an H-Plane radiated electric
field pattern, i.e., horizontal polarization, by a first antenna of
the H-type monopole isolation antenna in accordance with the
embodiment of the present invention;
[0029] FIG. 8 is a smith chart showing the H-plane radiated
electric field pattern, i.e., the horizontal polarization, by a
second antenna of the H-type monopole isolation antenna in
accordance with the embodiment of the present invention;
[0030] FIG. 9 is a view showing an H-type monopole isolation
antenna being fixed on a wall and used in accordance with an
embodiment of the present invention; and
[0031] FIG. 10 is a view showing the H-type monopole isolation
antenna being used as a device integrated with a power outlet in
accordance with the embodiment of the present invention.
MODE FOR THE INVENTION
[0032] Other objects and advantages of the present invention will
become apparent from the following description of the embodiments
with reference to the accompanying drawings. Therefore, those
skilled in the art that the present invention is included can
embody the technological concept and scope of the invention easily.
In addition, if it is considered that detailed description on prior
art may blur the points of the present invention, the detailed
description will not be provided herein. The preferred embodiments
of the present invention will be described in detail hereinafter
with reference to the attached drawings.
[0033] FIG. 1 is a perspective view showing an H-type monopole
isolation antenna in accordance with an embodiment of the present
invention.
[0034] As shown in FIG. 1, the H-type monopole isolation antenna of
the present invention includes an antenna device 1 for generating
radiated electromagnetic wave or receiving electromagnetic wave,
and an antenna supporter 2 for supporting the antenna device 1.
[0035] The antenna device 1 includes a covering housing 3, which is
covered with a conductor such as gold, silver, aluminum and copper,
and have a space inside, and first and second antennas 4 and 5,
which are separately set up in both sides of the covering housing
3.
[0036] The first antenna 4 is an H-type monopole antenna and
vertically positioned on top of the covering housing 3.
[0037] Also, the first antenna 4 includes a first antenna feeder 6
for feeding the antenna in a central part of an H-shaped form.
Herein, feeding through the first antenna feeder 6 is performed
horizontally to the covering housing 3.
[0038] The second antenna 5 is a general monopole antenna and is
positioned in a region in contact with the covering housing 3, and
includes a second antenna feeder 7 for vertically feeding the
covering housing 3.
[0039] The antenna supporter 2 includes an antenna device supporter
8 and an antenna base 9 for supporting the antenna device 1.
[0040] Herein, the antenna device supporter 8 is formed in the
shape of a pipe having a space inside and is set up in a central
part of the antenna device 1 as shown in FIG. 1.
[0041] The embodiment of FIG. 1 has a structure that horizontal
polarization is generated with respect to an earth surface.
[0042] Therefore, since reflection by the earth surface is
generated a lot in the horizontal polarization in comparison with a
vertical polarization and the reflected wave deteriorates
transmitting/receiving isolation, the antenna base 9 includes an
electric wave absorber 10 for suppressing the reflected wave to
remove the reflected wave.
[0043] Herein, reflexibility can be lowered by raising the height
of the antenna device supporter 8 as well as setting up the
electric wave absorber 10.
[0044] FIG. 2 is a cross-sectional front view of the antenna device
in accordance with the embodiment of the present invention and
shows a detailed structure of the first antenna feeder.
[0045] The first antenna 4 has a structure in which right and left
antenna devices 11 and 12 having a pipe shape formed of a metal
conductor such as gold, silver, copper and aluminum, are vertically
positioned in the covering housing 3 just as a monopole, and the
first antenna feeder 6 for feeding power is positioned in a region
where right and left antenna supporters 13 and 14 contact each
other between the right and left antenna devices 11 and 12.
[0046] As shown in the drawing, the first antenna feeder 6 includes
a first connector 15 and a first connector pin 16.
[0047] Herein, the right and left antenna supporters 13 and 14 are
formed in the shape of a conductive pipe.
[0048] A front head of the first connector 15 is positioned in the
inside of the right antenna supporter 13, and the first connector
pin 16 is welded into the left antenna supporter 14. Accordingly,
the first antenna 4 has a structure that the first antenna 4 feeds
horizontally a metal surface of the covering housing 3.
[0049] A coaxial cable connected to the first connector 15 is
connected to the inside of the covering housing 3 having a space
inside through the inside of the right antenna supporter 13 and the
inside of the right antenna device 11.
[0050] Meanwhile, the covering housing 3 is directly connected to
the antenna device supporter 8 through an opening 19 of the antenna
device supporter.
[0051] FIG. 3 is a cross-sectional side view showing the antenna
device in accordance with the embodiment of the present invention
and shows the second antenna feeder 7 in detail.
[0052] As shown in FIG. 3, the second antenna feeder 7 has a
structure that the second connector 17 is set up in the covering
housing and the second connector pin 18 is connected to the second
antenna.
[0053] A front head of the second connector 17 is positioned in the
inside of the covering housing 3 and formed to be able to connect
the coaxial cable.
[0054] Although an antenna feeding point is entirely wrapped and
fixed by using a dielectric to stand firmly against an external
environment such as wind (not shown in the drawing), it does not
affect a characteristic a lot.
[0055] Meanwhile, antenna devices 11 and 12 of the first antenna
are formed in the shape of a pipe having a space inside and are
directly connected to the inside of the covering housing 3 through
an opening 20 of the first antenna device.
[0056] FIG. 4 is a cross-sectional plane view showing an antenna
device in accordance with the embodiment of the present invention.
It shows positions of the right and left antenna supporters 14 and
15 of the first antenna in right and left antenna devices 12 and
13.
[0057] Also, as described above, the drawing shows that the first
connector 15 connected to the first antenna feeder can be connected
in an inside of the covering housing 3 through the coaxial
cable.
[0058] As described above with reference to FIGS. 2 and 3, the
antenna device supporter 8 should be positioned in a center of the
antenna device 1 to position the antenna device supporter 8 in the
center of the antenna device 1 where the right and left antenna
devices 12 and 13 of the first antenna, which is the H-type
monopole antenna, are symmetrically positioned.
[0059] This is for the following two objects.
[0060] One is to make the radiated electromagnetic wave and
scattered wave by the antenna device supporter 8 arrive at the
right and left antenna devices 11 and 12 in the same phase and same
intensity, when the second antenna is excited with a
transmitter.
[0061] Since it makes an electric potential difference between the
right and left antenna supporters 13 and 14 identical, it prevents
the radiated electromagnetic wave and scattered wave from being
received after offset in the H-type monopole antenna, which is the
first antenna.
[0062] The other one is also to make the radiated wave and the
scattered wave arrive at the right and left antenna devices in the
same phase and the same intensity, when radiated wave excited by
the first antenna forms scattered wave by a surface and arrives at
the second antenna. Herein, a technology for offsetting and
decreasing a signal transmitted from the first antenna, which is
the H-type monopole antenna, is added.
[0063] The antenna device supporter 8 can be formed in a pipe shape
19 by the conductors such as gold, silver, copper and aluminum. The
coaxial cable connected to the first and second antennas in the
inside of the pipe is sent under the surface and can be used by
being connected to the repeater or the communications system.
[0064] The left and right antenna devices 11 and 12, the left and
right antenna supporters 13 and 14, and the antenna device
supporter 8 of the first antenna can be formed in the shape of a
cylindrical pipe, of which a cross section is a circle.
[0065] FIG. 5 is a graph showing S parameter characteristics of the
H-type monopole isolation antenna in accordance with the embodiment
of the present invention.
[0066] A reference specification of an antenna used for measuring
is as follows.
[0067] The second antenna has a width of 1 cm.times.1 cm and an
entire length of 15 cm, and the first antenna also has the width of
1 cm.times.1 cm, which is the same as the second antenna. The
left/right antenna devices 11 and 12 have a length of 13 cm, and a
distance between the left/right antenna devices 11 and 12 is 6 cm.
The covering housing has a size of 2 cm.times.16 cm.times.20
cm.
[0068] As shown in FIG. 5, resonance of the first antenna and the
second antenna is generated at 550 MHz.
[0069] Herein, all values of S11 and S22 parameters are equal to or
smaller than -10 dB and it shows that impedance matching is well
performed.
[0070] The measurement result shows that the H-type monopole
antenna, which is the first antenna, can be used as the
transmitting/receiving antenna although the H-type monopole antenna
is independently operated.
[0071] Also, FIG. 5 shows that a ratio of electromagnetic wave
abandoned in the H-type monopole antenna, which is the first
antenna radiated to the electromagnetic wave through the
transmitting antenna is maintained at -75 dB and under when the
monopole antenna, which is the second antenna, is used as the
transmitting antenna. Herein, the rate means an S.sub.12
characteristic showing the isolation.
[0072] That is, although a length of the covering housing is
smaller than a half-wave length, high isolation is acquired.
Herein, half-wave of 550 MHz is 27 cm.
[0073] The isolation is varied based on the size of the covering
housing. It will be described hereinafter with reference to FIG. 6
that isolation is varied by the antenna device when the size of the
covering housing is varied in the range of 20 cm to 80 cm.
[0074] FIG. 6 is a graph showing the S.sub.12 parameter
characteristics based on the size of a covering housing of the
H-type monopole isolation antenna in accordance with the embodiment
of the present invention.
[0075] As shown in FIG. 6, when the size of the covering housing
increases in a range of 20 cm to 80 cm, isolation ratio is improved
by about 30 dB.
[0076] Also, when the size of the covering housing is 60 cm, the
isolation rate is maintained at about -100 dB. That is, when the
covering housing maintains about 1 wavelength, the isolation is
maintained at about -100 dB.
[0077] FIG. 7 is a smith chart showing an H-Plane radiated electric
field pattern, i.e., horizontal polarization, by a first antenna of
the H-type monopole isolation antenna in accordance with the
embodiment of the present invention.
[0078] As shown in FIG. 7, a gain is maintained at 1.8 dBi and
shows a semi-omni-directional characteristic in an H plane.
[0079] Herein, the polarization shown in the drawing is a pattern
for an electric field element of an .psi. direction.
[0080] FIG. 8 is a smith chart showing the H-plane radiated
electric field pattern, i.e., the horizontal polarization, by a
second antenna of the H-type monopole isolation antenna in
accordance with the embodiment of the present invention.
[0081] As shown in FIG. 8, when the second antenna is fed in a
structure that a monopole is horizontally positioned, a gain is
about 2.6 dBi and left and right patterns are formed.
[0082] Herein, the patterns are largely generated in a direction
toward the first antenna by scattered wave abandoned in the first
antenna.
[0083] The polarization is the pattern for the electric field
element of the direction as FIG. 7.
[0084] Also, as shown in the drawing, a section, in which beam
directions of FIGS. 7 and 8 are the same, is generated. That is,
both beam directions are the same in directions of 100 to 145
degree and 215 to 260 degree and it means that communications with
a terminal in the beam section are possible in a co-channel.
[0085] That is, it shows that the present invention can be used as
a bi-directional repeater system, a Radio Frequency Identification
(RFID) reader antenna, a wireless Local Area Network (LAN) low
output bi-directional repeater antenna and a Radar Cross Section
(RCS) measuring antenna.
[0086] Also, the present invention can be used as a uni-directional
horizontal polarization repeater antenna which can transmit a
signal transmitted from a direction of .psi.=180 by the first
antenna to directions of .psi.=100 to 145, and .psi.=215 to 260 by
the second antenna.
[0087] FIG. 9 is a view showing an H-type monopole isolation
antenna being fixed on a wall and used in accordance with an
embodiment of the present invention. It also shows a method using
the H-type monopole isolation antenna in vertical polarization
communications.
[0088] As shown in FIG. 9, the H-type monopole isolation antenna of
the present invention can be independently set up in a wall of a
building, or used by connecting to a communication system in the
inside of a building.
[0089] When the H-type monopole isolation antenna is used by
setting up the antenna device supporter 8 on a wall 22 where a
fixed iron is fixed, the isolation suggested above can be
maintained.
[0090] Also, when the antenna device is rotated up and down as much
as 90 degree the communications system for the horizontal
polarization can be supported.
[0091] FIG. 10 is a view showing the H-type monopole isolation
antenna being used as a device integrated with a power outlet in
accordance with the embodiment of the present invention.
[0092] As shown in FIG. 10, the H-type monopole isolation antenna
of the present invention can realize a system to which power is
supplied through an outlet in vertical polarization communications,
such as a bi-directional repeater system, an RFID reader system, a
wireless LAN low output bi-directional repeater system and a
monitoring system by equipping all circuits in the inside of the
covering housing by equipping an outlet 23 in one end of the
antenna device supporter 8.
[0093] In this case, it is very convenient that the present
invention can be simply and independently set up wherever a power
code, i.e., the outlet is.
[0094] While the present invention has been described with respect
to certain preferred embodiments, it will be apparent to those
skilled in the art that various changes and modifications may be
made without departing from the scope of the invention as defined
in the following claims.
* * * * *